Semi-crystalline fructose in solid form and process for manufacturing the same

ABSTRACT

A fructose in solid form containing a matrix and a plurality of carbohydrate crystals within said matrix, the matrix containing amorphous fructose and water, wherein the carbohydrate crystals comprise fructose and optionally one or more other carbohydrate(s), and optionally wherein the fructose in solid form is coated with a dry powder coating.

FIELD OF THE INVENTION

The present invention relates to solidified fructose, to a process forproducing solidified fructose and various uses of the solidifiedfructose e.g. in food, feed, personal care, pharmaceutical andindustrial applications.

BACKGROUND OF THE INVENTION

Fructose is a monosaccharide also known as fruit sugar. Fructose has ahigher sweetness than that of sucrose, and although it has the samecaloric value as sucrose, due to its higher sweetness, it can be used inlesser amounts to obtain a similar sweetness than when sucrose is used.

Commercially, fructose is typically produced by isomerization ofglucose. However, various challenges exist not only in the manufacturebut also in the supply chain of fructose and in particular when thefructose is used in the food or pharmaceutical industry.

In the food and pharmaceutical industry, fructose is generally used inthe form of fructose syrups containing between 9 and 90% by weight offructose. Syrups having a low content of fructose (e.g. below 9 wt %)and consequently a high content of water, are less preferred by theseindustries since shipping them might imply higher transportation costs.The syrups typically have short shelf life, which may be due toinstability, and may be affected by fructose crystallization, inparticular during storage. Such crystallization is detrimental to theend user in that it changes the fructose content of the product thatremains in syrup form and consequently it may become harder to handle.In particular dosing a syrup containing crystallized fructose may beincreasingly difficult and may render a product containing thereof,heterogeneous.

Fructose is also available in solid form, as crystalline fructose or assemi-crystalline fructose. Crystalline fructose is typically afree-flowing product and consists essentially of fructose crystals withno amorphous formations. For many applications, fructose in solid,powder form is preferred, and sometimes even required, as it is easierto handle, store and dose than fructose syrups.

Crystalline fructose is produced by a number of well-known processes,including the so-called Starcosa process, described in U.S. Pat. No.4,681,639, and those described in WO 03/016577, U.S. Pat. Nos. 3,513,023and 4,938,804.

A number of prior-art processes describe the production ofsemi-crystalline fructose. Semi-crystalline fructose refers to fructosehaving crystalline fructose and amorphous fructose, typically in a ratioof about 1:1, usually the crystalline fructose content is much higherthan the content of amorphous fructose.

U.S. Pat. No. 4,517,021 relates to semi-crystalline fructose productcomprising less than about 2 wt % water and greater than about 60 weight% of crystalline fructose.

U.S. Pat. No. 3,929,503 relates to the preparation of anhydrousfree-flowing solid particles of fructose by mixing crystalline fructosewith fructose syrup and wherein the quantities of crystalline fructoseused a much higher than the quantities of the fructose syrup, forexample in a ratio crystalline fructose to fructose syrup of 4:0.4 or4:1.55.

U.S. Pat. No. 4,681,639 relates to a process for producing a flowabledry product made of isoglucose syrup.

U.S. Pat. No. 3,956,009 relates to a process for preparing dried, solid,particulate fructose products from fructose solutions by drying thesolution in a current of heated air and in the presence of separatelyintroduced recycled dried product solids.

EP 0 195 610 describes a continuous process for the crystallization offructose from an aqueous fructose syrup containing at least 90% byweight fructose on a dry solids basis, in which the syrup at a totalsolids content of at least 95% by weight is rapidly and thoroughly mixedwith seed (fructose), at a temperature of 55-75 C e.g. for up to 2minutes; is then deposited on a surface where it is allowed tocrystallize under quiescent conditions at a temperature of 50-70 C,until a solid cake is formed; and is then comminuted to provide afree-flowing granular product which can be further dried.

Fructose crystallization processes are, however, difficult to operate,time-consuming, rather expensive and often result in a low yield offructose and a large number of by-products, a so-called mother liquor.These disadvantages limit the use of crystalline fructose in food andpharmaceutical products.

There is thus a need for fructose in solid form, in particular in powderform, that can be produced in a more cost- and/or time-efficient mannerIn particular, there is a need for a high-yield process for producingsolid fructose, preferably in continuous mode, and in particular a solidfructose powder. There is also a need for cost- and/or time-efficient,high-yield processes, which produce solid fructose of high fructosepurity or a solid fructose of specific properties, for example by addingother carbohydrates. There is also a need for such a process to yield asolid fructose powder with long-term stability (its properties do notsubstantially change with time) and easy handling (e.g. goodflowability).

The present invention seeks to mitigate or alleviate the drawbacks ofthe prior art and to provide an improved fructose product and anoptimized process for manufacturing thereof.

SUMMARY OF THE INVENTION

The invention relates to a fructose in solid form containing a matrixand a plurality of carbohydrate crystals within said matrix, the matrixcontaining amorphous fructose and water, wherein the carbohydratecrystals comprise fructose and optionally one or more othercarbohydrate(s), and wherein the fructose in solid form is optionallycoated with a dry powder coating.

Preferably, the one or more other carbohydrate(s) are selected fromsweeteners and polyols. More preferably the one or more othercarbohydrate(s) have a glass transition temperature (Tg) higher than theTg of fructose.

However, if the carbohydrate crystals consist of (or contain only)crystals of fructose, then the fructose in solid form is preferablycoated with a dry powder coating, preferably with a dry powder coatingthat is different from or does not consist of (or contain only)fructose.

The invention also relates to a fructose in solid form containing amatrix and a plurality of fructose crystals within said matrix, thematrix containing amorphous fructose and water, wherein the fructose insolid form is preferably coated with a dry powder coating, preferablywith a dry powder coating that is different from or does not consist of(or contain only) fructose.

The invention also relates to a powder containing particles, theparticles comprising the fructose in solid form.

The inventors observed that the fructose in solid form in accordancewith the invention, hereinafter “the inventive fructose”, can beproduced in a time- and cost-efficient manner In addition, the inventivefructose is of a high purity, good flowability and long-term stability.By adding other carbohydrates it is also possible to obtain otherspecific properties of the inventive fructose, also with goodflowability and long-term stability.

The invention, further relates to a method of manufacturing solidifiedfructose, in particular the inventive fructose, comprising:

-   -   (i) Providing an aqueous fructose solution having a dry        substance (DS) of at least 80 wt % relative to the total mass of        the solution;    -   (ii) Providing a powder containing particles comprising a        carbohydrate material;    -   (iii) Adding the powder to the aqueous fructose solution to        obtain an aqueous slurry having a glass transition temperature        (T_(g));    -   (iv) Cooling the aqueous slurry to a temperature of at most the        T_(g) of said slurry thereby obtaining a product containing        solidified fructose;    -   (v) Optionally milling the product containing the solidified        fructose and/or coating the solidified fructose or the milled        solidified fructose.

The inventors observed that the process in accordance with theinvention, hereinafter “the inventive process”, can produce theinventive fructose in a cost- and time-efficient manner but also in highyield. In particular, the inventive process may be designed to run withincreased efficiency in the sense that it may use a low amount of energyand/or the amount of waste material (e.g. mother liqueour) may be keptto a minimum and even to zero waste. Consequently, there may be no needof a recycling step of waste streams in the inventive process.Furthermore, the obtained solid fructose powder is stable and can behandled easily. Other advantages of the invention will become apparentfrom the detailed description given hereunder.

The invention further relates to a food, feed, personal care,pharmaceutical or industrial product comprising the inventive fructose.

The invention further relates to the inventive fructose obtainableaccording to the inventive process.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a fructose in solid form containing a matrixphase and a dispersed phase, the dispersed phase being dispersed withinsaid matrix, the matrix phase containing amorphous fructose and thedispersed phase containing a plurality of carbohydrate crystals, whereinoptionally the fructose in solid form is coated with a dry powdercoating.

The carbohydrate crystals can be crystals comprising fructose andoptionally one or more other carbohydrate(s). Preferably, the one ormore other carbohydrate(s) have a glass transition temperature (Tg)higher than the Tg of fructose.

However, if the carbohydrate crystals consist of (or contain only)crystals of fructose, then the fructose in solid form is preferablycoated with a dry powder coating, wherein the dry powder coatingpreferably is different from or does not consist of (or contain only)fructose.

The invention also relates to a fructose in solid form, containing amatrix phase and a dispersed phase, the dispersed phase being dispersedwithin said matrix, the matrix phase containing amorphous fructose andthe dispersed phase containing a plurality of fructose crystals. In sucha case, where the carbohydrate crystals consist of (or contain only)crystals of fructose, the fructose in solid form is preferably coatedwith a dry powder coating, preferably with a dry powder coating that isdifferent from or does not consist of (or contain only) fructose.

The invention also relates to a powder containing particles comprisingthe inventive fructose.

The following applies to all of the inventive fructose disclosed herein:

The inventive fructose is in solid form, i.e. said fructose canessentially retain its shape for at least 1 hour when placed on a flatsurface at a temperature less than 40° C. and at a relative humidityless than 80%. The inventive fructose may have any regular or irregularshape, e.g. powder, fibres, a block, and the like.

The inventive fructose contains a matrix phase and a dispersed phase.The matrix phase is herein understood a continuous phase embedding thedispersed phase. The dispersed phase is dispersed, preferablyhomogeneously, inside the matrix phase.

Preferably, the matrix phase is present in an amount of at least 85% DS,more preferably at least 90% DS, even more preferably at least 95% DSand most preferably said amount is at most 99% DS.

The matrix phase of the inventive fructose contains amorphous fructose.By amorphous fructose is herein understood a solid formed atnon-equilibrium conditions either by removing the dispersing medium(such as water), or from the melt by cooling, or by rapid supercooling.This material is not at thermodynamic equilibrium, and therefore isunstable relative to the crystalline form. The amorphous fructose ispreferably present in an amount of at least 0.1 wt % relative to thetotal mass of the inventive fructose, more preferably at least 5.0 wt %,most preferably at least 10.0 wt %. Preferably, said amount of amorphousfructose is at most 80 wt %, more preferably at most 30 wt %, mostpreferably at most 25 wt %. Preferably, said amount of amorphousfructose is between 0.1 wt % and 80 wt %, more preferably between 5 wt %and 25 wt %, most preferably between 10 wt % and 15 wt %.

The matrix phase may also contain water. The water is preferably presentwithin the matrix phase in an amount of preferably at least 0.2 wt %relative to the total mass of the inventive fructose, more preferably atleast 2.0 wt %, most preferably at least 5.0 wt %. Preferably, saidamount of water is at most 20 wt %, more preferably at most 15 wt %,most preferably at most 10 wt %. Preferably, said amount of water isbetween 0.2 wt % and 20 wt %, more preferably between 2 wt % and 15 wt%, most preferably between 5 wt % and 10 wt %.

The matrix phase may also contain impurities typically in an amount ofbetween 1 and 20 wt %. These may be impurities initially present in thefructose solution or introduced during the manufacturing process.

The dispersed phase is distributed inside the matrix phase, saiddispersed phase containing carbohydrate crystals comprising fructosecrystals and optionally one or more other carbohydrate(s). By beingdistributed inside the matrix phase it is herein understood that thecrystals are distributed or dispersed inside said matrix phase. Saidcrystals may be present inside the matrix phase as singular crystals oras clusters as crystals or combinations thereof. By crystals is hereinunderstood as including the solid material (preferably carbohydratematerial) added to the solution to give rise to the aqueous slurry ofstep iii. This slurry may enhance the crystallization of the solutefructose in the matrix phase. The dispersed phase is preferably presentin an amount of at least 3 wt % relative to the total mass of theinventive fructose, more preferably at least 5 wt %, 10 wt %, 15 wt % or20 wt %, even more preferably at least 70 wt %, most preferably at least75 wt %. Preferably, said amount of carbohydrate crystals, includingfructose crystals, is at most 99.8 wt %, more preferably at most 90 wt%, most preferably at most 80 wt %. Preferably, said amount ofcarbohydrate crystals, including fructose crystals, is between 3 wt %and 99.8 wt %, more preferably between 5 wt %, 10 wt %, 15 wt % or 20 wt% and 99.8 wt %, even more preferably between 70 wt % and 90 wt %, mostpreferably between 75 wt % and 80 wt %. The amount of crystals willdepend on the particle size of the crystals, as is known to a personskilled in the art.

The one or more other carbohydrates can be present from at least 1, 3,5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 92, 95, 97, 98, 99 or 99.5 wt% of the total amount of carbohydrate crystals present in the inventivefructose. The one or more other carbohydrates can be present at at most99.5, 99, 98, 97, 95, 92, 90, 80, 70, 60, 50, 40, 30, 20, 15, 10, 5, 3or 1 wt % of the of the total amount of carbohydrate crystals present inthe inventive fructose.

The carbohydrate crystals can be crystals comprising fructose andoptionally one or more other carbohydrate(s). Preferably, the one ormore carbohydrate(s) are selected from sweeteners and/or polyols.Preferably the sweetener is selected from dextrose, maltose,isomaltuose, mannose, sucrose, lactose, trehalose, galactose, raffinoseand mixtures thereof. Preferably the polyol is selected from sorbitol,xylitol, erythritol, maltitol, isomalt, isomaltitol, mannitol andmixtures thereof. More preferably, the one or more carbohydrate(s) areselected from carbohydrates having a glass transition temperature (Tg)higher than the Tg of fructose. Most preferably the sweetener isselected form dextrose, sucrose, maltose, isomaltulose, lactose,raffinose and mixtures thereof. Most preferably the polyol is selectedfrom maltitol, isomalt, mannitol and mixtures thereof. Preferably thecarbohydrate crystals, which have been added during the seeding process(i.e. in step iii), are different from or do not consist of (or containonly) crystals of fructose.

If the carbohydrate crystals consist of (or contain only) crystals offructose, then the fructose in solid form is preferably coated with adry powder coating, wherein the dry powder coating preferably isdifferent from fructose or does not consist of (or contain only)fructose. Suitable coating material is described below and will not berepeated here.

The matrix phase and/or the dispersed phase may further containinternally, various carbohydrates, non-limiting examples thereofincluding dextrose, maltose, sorbitol, stevia and mixtures of one ormore thereof. Further examples of suitable carbohydrate materials aregiven herein below. By “containing internally” it is herein understoodthat the carbohydrates are present inside said phases, i.e. in the bulk.If present, the carbohydrate material is preferably comprised in anamount of at most 49 wt % DS, relative to the total combined amount ofthe matrix and dispersed phases, preferably at most 25 wt % DS, morepreferably at most 20 wt % DS, even more preferably at most 15 wt % DS,yet even more preferably at most 10 wt % DS, yet even more preferably atmost 5 wt % DS, yet even more preferably at most 2 wt % DS, mostpreferably at most 1 wt % DS.

The inventive fructose is preferably in the form of a powder. The powdercontains particles comprising the inventive fructose and preferablyhaving a D50 of at least 10 μm, more preferably at least 50 μm, evenmore preferably at least 100 μm, most preferably at least 150 μm.Preferably, said D50 is at 2500 μm, more preferably at most 700 μm, evenmore preferably at most 300 μm, most preferably at most 200 μm.Preferably, said D50 is between 10 μm and 2500 μm, more preferablybetween 50 μm and 700 μm, most preferably between 150 μm and 200 μm.

Preferably, the particles have a D90 of preferably at least 20 μm, morepreferably at least 80 μm, even more preferably at least 150 μm, mostpreferably at least 200 μm. Preferably, said D90 is at most 3000 μm,more preferably at most 1000 μm, even more preferably at most 500 μm.Preferably, said D90 is between 20 μm and 3000 μm, more preferablybetween 80 μm and 1000 μm, most preferably between 100 μm and 500 μm.

The particle size distributions D50 and D90 and the mean particlediameters (mean volume diameter of particle diameters: MV) of theparticles forming the powder were measured by laser diffraction (BeckmanCoulter, LS 13 320, Miami, Fla.) as detailed in the MEASURING METHODSsection of the description.

Preferably, said particles are coated with a dry powder coating, whichmay advantageously provide said particles with non-stickiness abilitiesand may provide the powder with good flow properties. By dry powdercoating is herein understood a coating in the form of a powder having amoisture content of at most 20 wt % based on the total weight of thepowder. Preferably, the moisture content is at least 0.1 wt %, morepreferably at least 1.0 wt %, even more preferably at least 2.0 wt %,most preferably at least 5.0 wt %. Preferably, said moisture content isat most 20 wt %, more preferably at most 15 wt %, most preferably atmost 10 wt %. Preferably, said moisture content is between 0.1 wt % and20 wt %, most preferably between 0.1 wt % and 10 wt %.

The dry powder coating contains coating particles, said coatingparticles having a D50 that is at least 15% smaller than the D50 of theparticles forming the powder, more preferably at least 20% smaller, evenmore preferably at least 25% smaller, yet even more preferably at least30% smaller, most preferably at least 35% smaller. Preferably, saidcoating particles are at most 75% smaller than the D50 of the particlesforming the powder, more preferably at most 60% smaller, most preferablyat most 60% smaller.

Any material may be used for the particles of the dry powder coating.This is preferably any material that can prevent water absorption and/orstickiness of the inventive fructose. Preferably, the coating particlescontain a carbohydrate material. Non-limiting examples of thecarbohydrate material include sweeteners, starches including modifiedstarches, hydrocolloids, polyols, dextrins, maltodextrins, food-gradepolymers, biopolymers and the like and mixtures thereof. Most preferredcarbohydrate materials are sweeteners and polyols.

The sweetener may be a nutritive sweetener, a high intensity sweetenerand mixtures thereof. Non-limiting examples of nutritive sweetenersinclude sucrose, maltose, lactose, glucose, and galactose. The nutritivesweetener may also be a fructose different than the inventive fructose,preferably a crystalline fructose with a crystallinity of above 95%. Thehigh intensity sweetener may be selected among aspartame, acesulfamesalts such as acesulfame-K, saccharins, cyclamates, sucralose, alitame,neotame, steviosides, glycyrrhizin, neohesperidin dihydrochalcone,monellin, thaumatin, brazzein and mixture of two or more thereof.Preferably the high intensity sweetener is stevia.

The polyol may be selected among the tetritols, pentitols, hexitols,hydrogenated disaccharides, hydrogenated trisaccharides, hydrogenatedtetrasaccharides, hydrogenated maltodextrins and mixture thereof. Morespecifically, the polyol can be selected from the group consisting oferythritol, threitol, arabinitol, xylitol, ribitol, allitol, altritol,gulitol, galactitol, mannitol, sorbitol, talitol, maltitol, isomaltitol,isomalt, lactitol and mixtures of two or more thereof. Preferably thepolyol is maltitol, sorbitol, isomalt or a mixture of two or morethereof.

In a preferred embodiment, the dry powder coating contains particlecontaining the inventive fructose and having a particle sizedistribution within the ranges described hereinabove in relation to saidcoating. The dry powder coating of this embodiment can be obtained byfinely milling the inventive fructose.

Preferably, the dry powder coating contains particles comprisingdextrose, stevia, sorbitol, fructose different than the inventivefructose, inventive fructose or mixtures thereof.

However, if the carbohydrate crystals consist of (or contain only)crystals of fructose, then the dry powder coating preferably isdifferent from or does not consist of (or contain only) fructose, butmay contain one or more of the materials mentioned for the dry coatingabove.

The invention further relates to a powder (hereinafter referred to as“the inventive powder”) containing particles, said particles comprisingthe inventive fructose. Preferred embodiments of the particles are givenhereinabove and will not be repeated herein.

Preferably the inventive powder has a moisture content of from 0.1 to20.0 wt %.

The inventors observed that the inventive fructose and the inventivepowder are highly soluble, they can easily be dissolved in water at roomtemperature (at 20° C.) up to amounts of 3760 g/l. Preferably, theinventive fructose and the inventive powder have a solubility of atleast 700 g/l, more preferably at least 1000 g/l, most preferably atleast 3750 g/l.

The particles forming the inventive powder may also be in the form ofagglomerates. If present, said agglomerates preferably have a meandiameter of from 0.2 to 10 mm, more preferably from 0.3 to 5 mm, mostpreferably from 0.8 to 1.5 mm. Mean diameter may be measured by means ofa sieving procedure and/or dimensional analysis of images under anoptical microscope.

The inventors surprisingly observed that the inventive fructose has awhite colour, i.e. it is characterized by a CIELAB L* value of at least85, more preferably at least 90, most preferably at least 95.Preferably, the CIELAB b* value is at most 100, more preferably at most99, most preferably at most 98.

The inventors surprisingly observed that the inventive powder has anoptimum flowability. Preferably, the flowability of said powder isbetween 20 and 45 degrees [Angle of response], more preferably between25 and 45, most preferably between 30 and 35.

The inventors surprisingly observed that the inventive powder and/or theinventive fructose may have an optimum hydrophilicity. Preferably, thehydrophilicity thereof is between 15% and 50% [mass increase at standardtest conditions], more preferably between 20% and 45%, most preferablybetween 30% and 40%.

The invention, further relates to a method of manufacturing solidifiedfructose, in particular the inventive fructose, (hereinafter the“inventive method”) comprising:

-   -   (i) Providing an aqueous fructose solution having a dry        substance (DS) of at least 80 wt % relative to the total mass of        the solution;    -   (ii) Providing a powder containing particles comprising a        carbohydrate material;    -   (iii) Adding the powder to the aqueous fructose solution to        obtain an aqueous slurry having a glass transition temperature        (T_(g));    -   (iv) Cooling the aqueous slurry to a temperature of at most the        T_(g) of said slurry thereby obtaining a product containing        solidified fructose;    -   (v) Optionally milling the product containing the solidified        fructose and/or coating the solidified fructose or the milled        solidified fructose.

The aqueous fructose solution of step (i) preferably has a DS of atleast 85 wt %, more preferably at least 90 wt %. Preferably said DS isfrom 90 to 99.9 wt %, more preferably from 94 to 98 wt %, mostpreferably from 96 to 98 wt %.

Preferably, the temperature of the aqueous fructose solution is from 50°C. to 90° C., more preferably from 50 to 70° C., even more preferablyfrom 55 to 65° C. Preferably, the aqueous fructose solution ismaintained at such temperature under constant or regular stirring.Preferably, the aqueous fructose solution is kept under conditions suchthat the DS does not change. Any suitable means to maintain the aqueousfructose at a said temperature may be used and any suitable means ofstirring may be used.

The aqueous fructose solution may be obtained for example byconcentration of a less concentrated aqueous fructose solution such asan aqueous fructose solution having a DS content being less than the DScontent of the aqueous fructose solution of step (i). For example, saidless concentrated aqueous fructose solution may have a DS content offrom 10 wt % to less than 80 wt %, or from 20 wt % to 70 wt %, or from30 wt % to 50 wt %, or from 35 wt % to 45 wt %. Said less concentratedaqueous fructose solution preferably has a fructose purity of from 40 to95 wt %, preferably from 50 to 95 wt %, more preferably from 70 to 95 wt%, even more preferably from 80 to 95 wt %, yet even more preferablyfrom 90 to 95 wt %. By fructose purity it is herein understood fructosemass per overall DS mass.

Concentration of the less concentrated aqueous fructose solution may bedone by evaporation. Evaporation may be done by heating said lessconcentrated fructose solution at a temperature suitable to remove waterwithout affecting the physical properties of the fructose in thesolution, e.g. under vacuum. The evaporation temperature may be forexample from 50 to 90° C., preferably from 50 to 70° C., more preferablyfrom 55 to 65° C. Heating may be carried out in a double jacketed vesselusing water or any higher boiling point fluid as heating medium.Preferably heating is done in a closed system from which water isremoved in a controlled manner in order to obtain the desired DS.Preferably, stirring is applied during heating. More preferablycontinuous stirring is applied.

In step (ii) of the inventive method, a powder containing particlescomprising a carbohydrate material is provided. The particles preferablyhave a diameter (considering said particles spheres) of preferably atmost 3 mm, more preferably at most 2 mm. Preferably said diameter is atleast 150 μm, more preferably at least 500 μm, even more preferably atleast 1500 μm.

The carbohydrate material may comprise or consist of one or morecarbohydrate(s). The powder may thus contain particles, which compriseor consist of one or more carbohydrate(s).

The carbohydrate material may comprise or consist of fructose andoptionally one or more carbohydrate(s). The powder may thus containparticles, which comprise or consist of fructose and optionally one ormore carbohydrate(s).

The carbohydrate material may comprise or consist of one or morecarbohydrate(s) excluding fructose. The powder may thus containparticles, which comprise or consist of one or more carbohydrate(s)excluding fructose.

The carbohydrate material may comprise or consist of one or morecarbohydrate(s), which have a glass transition temperature (Tg) higherthan the Tg of fructose. The powder may thus contain particles, whichcomprise or consist of one or more carbohydrate(s), which have a glasstransition temperature (Tg) higher than the Tg of fructose.

Preferably, the one or more carbohydrate(s) are selected from sweetenersand/or polyols. Preferably the sweetener is selected from fructose,dextrose, maltose, isomaltuose, mannose, sucrose, lactose, trehalose,galactose, raffinose and mixtures thereof. Preferably the polyol isselected from sorbitol, xylitol, erythritol, maltitol, isomalt,isomaltitol, mannitol and mixtures thereof. More preferably, the one ormore carbohydrate(s) are selected from carbohydrates having a glasstransition temperature (Tg) higher than the Tg of fructose. Morepreferably the sweetener is selected form dextrose, sucrose, maltose,isomaltulose, lactose, raffinose and mixtures thereof. More preferablythe polyol is selected from maltitol, isomalt, mannitol and mixturesthereof.

Further suitable examples of the carbohydrate material are givenhereinabove in reference to the dry powder coating and will not berepeated herein. Preferably, said material is one or more nutritivesweeteners, one or more polyols (e.g. sorbitol), one or more highintensity sweeteners (e.g. stevia) or mixtures thereof. Most preferably,said carbohydrate material is the inventive fructose and/or theinventive powder, most preferably the inventive powder. When theinventive fructose and/or the inventive powder is/are used, the processmay use any of the other carbohydrate materials to produce said powderand/or said fructose in a suitable quantity for being used in step (ii)of the inventive method.

At step (iii) of the inventive method, the powder is added to theaqueous fructose solution to obtain an aqueous slurry. Preferably, theaddition is done by mixing. Mixing is preferably carried out to achievea homogeneous slurry, i.e. a slurry wherein the powder is homogeneouslydistributed. Mixtures and in particular homogeneous mixtures can beachieved by mixing the said powder and said solution at preferablyconstant temperature. Preferably, step (iii) is carried out at atemperature of at least 60° C., more preferably at least 65° C., evenmore preferably at least 68° C., most preferably at least 70° C.Preferably, said solution temperature is at most 90° C., more preferablyat most 85° C., even more preferably at most 80° C., most preferably atmost 75° C. Preferably, step (iii) is carried out by mixing at atemperature as indicated hereinabove. Mixing can be carried out with anymixing device known in the art such as for example a static mixingdevice, a high-speed mixing device and the like.

Mixing can be carried out for a mixing time of at least 1 sec and up to24 h. Preferably the mixing time is from 30 s to 40 minutes, morepreferably from 1 minute to 30 minutes, even more preferably from 5minutes to 20 minutes, most preferably from 15 minutes to 25 minutes.

During the mixing, the aqueous fructose solution and the powder areforming a slurry. The difference between a solution and a slurry is wellknown in the art, i.e. a slurry is a mixture containing the powder insolid phase dispersed within a liquid phase and may also containdissolved powder. A solution on the other hand means that the powder isdissolved and essentially no solid-phase exists therein.

Step (iii) of the inventive method may also be referred to as ‘seeding’.Seeding may induce fructose crystallization to some extent. Preferablythe powder is mixed with the aqueous fructose solution in an amount offrom 1 to 20 wt %, more preferably from 1 to 15 wt %, even morepreferably from 1 to 10 wt %, yet even more preferably from 2 to 10 wt%, yet even more preferably from 3 to 10 wt %, yet even more preferablyfrom 4 to 10 wt %, yet even more preferably from 5 to 10 wt %, mostpreferably from 8 to 10 wt %, based on the weight of the fructosesolution provided in step (i).

The aqueous slurry is characterized by a glass transition temperature(T_(g)). The T_(g) is the temperature at which a reversible transitionoccurs between a solid amorphous (glassy) state and a supercooled liquid(rubbery) state and is a parameter of critical importance to thestability of amorphous materials. T_(g) can be measured by usingdifferential scanning calorimetry (DSC). Typically, to determine T_(g) asample of the material is first cooled with 10 K/min and then heatedwith that same speed. For example, amorphous fructose, ornon-crystalline fructose, is typically characterized by a glasstransition temperature of between 7 and 17° C., however, it is wellknown that this temperature range can be significantly affected by thecomposition of the product as well as by the way of manipulation thereto(e.g. cooling). In particular, depending on the composition of thefructose slurry and the type of carbohydrate material used in theseeding step, the glass transition temperature can be varied.Preferably, the T_(g) of the aqueous slurry of step (iii) of theinventive method is at least −20° C., more preferably at least −10° C.,even more preferably at least −5° C., most preferably at least −2° C.Preferably, said T_(g) is at most 5° C., more preferably at 10° C., evenmore preferably at most 20° C., most preferably at most 40° C.

In step (iv), the slurry is cooled to a temperature of at most the T_(g)of said slurry, i.e. a temperature equal to or below said T_(g). The aimof this step is to cause the formation of a product (a slurry containingsolidified fructose) in a glassy state. Cooling to said temperatureinduces therefore the formation of solidified fructose inside theaqueous slurry and produces therefore a product containing saidsolidified fructose. The product may also contain water and thecarbohydrate material.

Preferably, the aqueous slurry is cooled at a cooling temperature of at1° C. below the T_(g) of said slurry, more preferably of at least 3° C.,even more preferably of at least 5° C., most preferably of at least 10°C. below the T_(g) of said slurry.

Cooling is preferably performed under atmospheric conditions atcontrolled humidity in order to prevent condensation of ambientmoisture. Preferably cooling is done in the presence of nitrogen orother inert gas. Preferably, the cooling is carried out in a coolingenvironment having a relative humidity of from 0 to 70%, more preferablyfrom 0 to 10%, most preferably from 0 to 5%. Preferably, the cooling israpid or quick cooling, i.e. quenching. The cooling is preferablycarried out with a cooling of between 40 and 120° C./sec, morepreferably of between 50 and 100° C./sec, most preferably of between 60and 80° C./sec.

Cooling may be performed by feeding the aqueous slurry into or ontocooling means. Preferably, said cooling means is provided with means tokeep the cooling temperature constant and continuously remove thesolidification heat released during the solidification process.

The cooling means may be a refrigerated surface, such as a refrigeratedbelt or refrigerated (revolving) disk for example. The cooling means mayalso be a cooled gas stream e.g. a cooled air stream or a cooled streamof nitrogen.

Advantageously, the feeding of the aqueous slurry into or onto thecooling means, is done in such a way that the obtained solidifiedfructose is in the form of particles, threads or filaments. Theparticles, threads or filaments may be of various sizes, e.g. variousdiameters, lengths and widths.

Preferably the feeding is carried out such that particles oragglomerated particles are formed, said particles being preferablyessentially spherical. If agglomerates are formed, the mean diameter ofthe agglomerates is preferably from 0.2 to 10 mm, more preferably from0.3 to 5 mm, most preferably from 0.8 to 1.5 mm. To achieve suchparticles and/or agglomerates, the aqueous slurry may be fed to thecooling means in the form of droplets. Most preferably, cooling is doneby feeding the aqueous slurry in the form of droplets onto arefrigerated belt.

After cooling, the product obtained may be milled in order to reduce itsparticle size to a desired particle size. Preferably, after milling, theproduct is obtained in the form of granules or agglomerates having amean diameter of from 0.3 to 4 mm, more preferably from 0.8 to 1.5 mm.Milling is thus not required in case the mean diameter of theagglomerates obtained after cooling is already in said range.

Milling can be done using standard milling apparatus such as finecutting mills, externally refrigerated to operate below the glasstransition temperature of the solidified product. Preferably alsomilling is performed under atmospheric conditions at controlledhumidity. The relative humidity may be from 0 to 70%, preferably from 0to 10%, more preferably from 0 to 5%.

After cooling, or after milling in case a milling step is performed, thesolidified fructose may be coated with the dry powder coating describedabove in the present description. The temperature during the coatingstep does not need to be strictly controlled. It is increased at orabove the glass transition temperature range, preferably up to theambient temperature. After coating, the solidified fructose may bestored at ambient temperature or it may be refrigerated. Preferably itis stored under sealed conditions.

The present invention further relates to food, feed, personal care,pharmaceutical or industrial product comprising the solidified fructoseof the present invention. The food product may be confectionery product,beverage, bakery, dairy, or frozen products. Solidified fructose mayalso be used as an excipient in pharmaceutical products such as powderedmedicines, tablets and the like.

Methods of Measurement

Moisture content (“MC”): The moisture content was determined with aninfrared moisture balance (MA30, Satorius). The sample was dried at 105°C. The moisture content (in wt %) was calculated as (A1−A2)/A1×100 whereA1 was the weight of the sample before drying in the oven and A2 was theweight of the resulted dried sample.

Dry substance content (“DS”) is measured according to formula:

DS (%)=100%−MC (%)

Particle size distribution: The particle size distribution was measuredby laser diffraction (Beckman Coulter, LS 13 320, Miami, Fla.). Sampleswere poured into a stirred tank, filled with pure ethanol and circulated2 times into the measuring cell (pumping rate 30%). Laser light having750 nm wavelength was used as the main laser light source, whereas laserlight having wavelength of 450, 600, and 900 nm was used forpolarization intensity differential scattering (PIDS). The detectionrange was 0.04-2000 μm. The volumetric particle size distributions ofthe samples were calculated from the intensity distributions of thescattered light according to the Fraunhofer optical model using theinstrument's software (plant cell wall RI=1.6, water RI=1.33 andabsorption coefficient for the dispersion 1) (Verrijssen et al., 2014).

Average particle size may be determined by ASTM C136-06.

Tg: A thermomechanical analysis (TMA) uses a small sample of material,which is heated on a quartz stage. A rod inside the machine places asmall amount of force on the top of the sample, and the movement of therod is measured with a linear variable differential transformer or LVDT.The entire instrument is heated at a slow rate, usually 5 degrees C. perminute. This data is reported as a curve, where change in length isplotted versus temperature. The slope of the resulting curve is calledthe coefficient of linear thermal expansion, or COLTE. The glasstransition temperature is the point at which the slope of the linechanges.

Microscopy Analysis: The microstructure of the non-homogenised andhomogenised samples was visualised by means of microscopy, usingspecific dyes and epifluorescent lightening, as well as normal light.The epifluorescent samples were stained with acridine orange (dilutionof 1:100 from 2% concentrated dye) and analysed using an Olympus BX-41microscope, equipped with an Olympus XC-50 digital camera andphoto-analysing software. Acridine orange was used as a cationic dyewhich associates with polyanionic compounds while emitting a greenfluorescence.

Flowability measurement method: The angle of repose is the angle(relative to the horizontal base) of the conical pile produced when agranular material is poured on to a horizontal surface. It is related tothe density, surface area and coefficient of friction of the materialconcerned. The angle of repose attachment comprises a 100 mm diametercircular test platform together with a digital height gauge having arange of 0-300 mm. For this particular test, the funnel is normallyequipped with a special 10 mm i.d. nozzle mounted 75 mm above the testplatform. The angle of repose can be determined by reading off theheight of the powder cone in mm from the digital display of the heightgauge and dividing the reading by 50.

Hydrophobicity measurement method: the degree of hygroscopicity of asubstance is defined based on the percentage increase of mass of thesubstance after 24 hours of exposure at 80±2 per cent relative humidityand 25±1° C. A substance is extremely hygroscopic if the mass increaseat the above conditions is equal or higher than 15%.

Measuring Color (CIELAB L*, b* values): CIE L*a*b* (CEILAB) is the mostcomplete color space specified by the International Commission onIllumination (Commission Internationale d'Eclairage). It describes allthe colors visible to the human eye and was created to serve as a deviceindependent model to be used as a reference. The L* and b* values areobtained by placing samples (in powder form) in the glass cell (fill thecell to about a half) of the colorimeter and analyse the sample inaccordance with the user's instructions of the colorimeter. Thecolorimeter used is a Minolta CR400 Colorimeter.

The invention will now be described with the help of the followingexamples and comparative experiments, without being however limitedthereto.

EXAMPLES Example 1

Approximately 500 g of 70% DS syrup of fructose 90% in purity wereevaporated in a jacketed vessel under vacuum, at an absolute pressure ofaround 0.05 bar. The syrup was gently stirred by means of a bladepropeller. The evaporation took place at 60° C. and the produced steamwent into a cylindrical condenser, fitted with a coil internallyrefrigerated by a thermostatic fluid at −1° C. The condensed water felldown into a cylindrical vessel maintained a few degrees over 0° C. Thecollected water amount was evaluated by the liquid height in the vesselat the condenser bottom. After a few hours, when the DS percentage wasaround 94%, 35 g of fructose, in the size range 75-250 μm, were pouredinto the syrup in order to induce a partial crystallization of theamorphous fructose. 10 minutes later a small amount of the slurry, atsemi-crystalline state, was withdrawn from the vessel, quenched over acylinder internally refrigerated at a temperature around 2° C. Due toits very rapid cooling, said quenching, the fructose slurry immediatelysolidified. The obtained solid product appeared transparent and fragile.The solid was then put in a cylindrical container, at 2° C., where itwas grinded down to particles between 500 μm and 2-3 mm. Finally, thefructose particles were put over a vibrating surface where they were letto jump together with 35 g of fructose powder, in the size range 25-250μm for 20 minutes. After the coating process the obtained fructoseparticles were separated from the coating powder by sieving. During thisdrying process, the temperature of the particles was naturally increasedfrom a few degrees until the ambient temperature and there was atransition of the solid from the glassy state to the rubber state. Thistransition was accompanied by a further transformation of the amorphousfructose to the crystalline fructose. The produced particles, quiterounded and non-sticky, were saved in a sealed sample holder. After aperiod of time of 30 days the particles exhibited no agglomeration, verylow fragility, thus their conditions appeared very stable. In FIG. 1,the obtained semi-crystalline fructose having an average particle sizeof about 1.2 mm is shown.

Solubility rate tests of the produced semi-crystalline particles wereperformed by comparison with the solubility rate of the pure crystallinefructose. Two separate runs were carried out by using an initial mass of1.5 g of fructose particles in the range size 425-600 μm. The solid wasstirred in a cylindrical vessel with distilled water at ambienttemperature. In both the runs the solid disappearance was detected after25 s, showing a quite equal solubility rate of the producedsemi-crystalline fructose with respect to the crystalline fructose.

Example 2

400 g of 70% DS syrup of fructose 87% in purity was evaporated asreported in Example 1, until a DS value equal approximately 94% wasreached. Then, 28 g of pure fructose was seeded and mixed with the syrupfor 10 minutes, when a homogeneous slurry was obtained. The flowabilityof the slurry appeared better with respect to that one of the slurry inExample 1, because of the presence of more than 5% of maltose, among theimpurities. The presence of fructose powder induced a partialcrystallization of the amorphous fructose. A sample of the slurry waswithdrawn and laid over a cooled surface, internally refrigerated ataround 2° C. The so-called semi-crystalline solid fructose at glassystate was removed from the cold surface and grinded in a refrigeratedvessel, down to a size of a few mm. Then, the produced solid particleswere let to jump with 30 g of fructose powder in the size range 25-250μm for 20 minutes. At the end of the overall process the characteristicsof the obtained particles resulted quite similar to those produced inExample 1.

Example 3

400 g of 70% DS syrup of fructose 87% in purity was evaporated asreported in Example 2, until a DS value equal approximately 94% wasreached. Then 28 g of solid fructose produced in Example 2, sieved at asize less than 1.25 mm, were seeded to induce the partialcrystallization of the amorphous fructose. After 10 minutes theagitation was stopped, and a sample of the slurry was put in contactwith a cooled surface internally refrigerated at around 2° C. The quenchof the slurry caused its sudden solidification at glassy state. Theobtained solid was removed from the cooled surface and grinded in arefrigerated container down to a particle size of a few mm. Thefollowing coating process was performed by let the produced particles tojump over a vibrating surface together with 30 g of the fructose powder,as used for seeding. During the coating process the solid, lasted 15minutes, the temperature rises from a few degrees ° C. up to ambienttemperature. During this period of time the solid transition from glassyto rubber state occurred and a further crystallization of the fructoseas well. At the end, the overall process the produced solid particlesenough hard to be well handled during the storage, were separated fromthe coating powder by sieving.

After a storage of 30 days the solid particles appeared to preservetheir original shape, to have a very good flowability and a goodhardness.

Example 4

400 g of 70% DS syrup of fructose 87% in purity was evaporated asreported in Example 2, until a DS value equal approximately 94% wasreached. Then 28 g of pure dextrose powder, 200 μm in size, were seededto induce the partial crystallization of the amorphous fructose. After10 minutes the agitation was stopped, and a sample of the slurry was putin contact with a cooled surface internally refrigerated at around 2° C.The quench of the slurry caused is sudden solidification at glassystate. The obtained solid was removed from the cooled surface andgrinded in a refrigerated container down to a particle size of a few mm.A coating was then performed by let the produced particles to jump overa vibrating surface together with 30 g of dextrose. During the dryprocess the solid, lasted 15 minutes, the temperature rises from a fewdegrees ° C. up to ambient temperature, dealing with its transition fromglassy to rubber state and a further crystallization of the fructose. Atthe end of the overall process, the produced solid particles hard enoughto be well and easily handled for and during storage, were separatedfrom the coating powder by sieving.

After a storage of 30 days the solid particles appeared to preservetheir original shape, to have a very good flowability and a goodhardness.

Comparative Experiment 1

For the sake of comparison, an experiment was carried out according tothe traditional prior art method to produce crystalline fructose bystarting from the same raw material as in Example 1, that is a 70% DSsyrup with 90% fructose purity.

The crystallization experiment was carried out firstly by evaporatingthe fructose syrup at 60° C. under vacuum until a DS value of 94% wasreached. Then 10 wt % of pure fructose powder was added for seeding andthe slurry was maintained under stirring for 20 minutes at constanttemperature. The slurry within the vessel was then cooled during thenight at ambient temperature, by simply stopping the circulation of thethermostatic stream trough the jacket. The slurry was filtered and theobtained crystals were dried. An image of the obtained crystals isprovided in FIG. 2. The average particle size was around 600 μm.

The collected mass of crystals (i.e. the yield) was less than 15% of theoverall solute. In this case, the mother liquor needs to be recycledi.e. the process has to be repeated to extract and obtain more finalproduct from the mother liquor, requiring high energy consumption andhigh costs.

On the contrary, the production process of the semi-crystalline fructoseproduct according to the invention led directly to the fructose finalproduct and no recycling streams were needed. In the process accordingto the invention, the production yield was equal to 100% of the solutefructose initially present in the syrup, whereas in the case of theprocess according to the prior art the yield was less than 15%.

Furthermore, there were differences in the duration of the process. Inthe process according to the invention, after the first evaporation, thefructose particles were obtained in less than 1 h (see Example 1),whereas the production of crystalline fructose according to the priorart required several hours.

Finally, the semi-crystalline fructose particles produced according tothe inventive method can be immediately packaged. However, this is notthe case of crystalline fructose produced according to the prior art,which requires further down-stream processing before packaging can takeplace, in particular the separation from the mother liquor, grinding anddrying.

1. A fructose in solid form containing a matrix and a plurality ofcarbohydrate crystals within said matrix, the matrix containingamorphous fructose and water, wherein the carbohydrate crystals comprisefructose and optionally one or more other carbohydrate(s), andoptionally wherein the fructose in solid form is coated with a drypowder coating.
 2. The fructose according to claim 1, wherein the drypowder coating is selected from sweeteners, starches, polyols, dextrins,and maltodextrins and mixtures thereof.
 3. The fructose according toclaim 1, wherein the carbohydrate crystals comprise fructose and one ormore other carbohydrate(s), wherein the one or more othercarbohydrate(s) are preferably selected from sweeteners and polyols. 4.The fructose according to claim 3, wherein the one or more othercarbohydrate(s) have a glass transition temperature (Tg) higher than theTg of fructose.
 5. The fructose according to claim 4, wherein thesweetener is preferably selected from dextrose, sucrose, maltose,isomaltulose, lactose, raffinose and mixtures thereof and/or the polyolis preferably selected from maltitol, isomalt, mannitol and mixturesthereof.
 6. A fructose according to claim 1, wherein the carbohydratecrystals consist of fructose and wherein the fructose in solid form iscoated with a dry powder coating that is different from fructose or doesnot consist of fructose.
 7. The fructose of claim 1, wherein the matrixphase is in an amount of at least 85% DS.
 8. The fructose of claim 1,wherein the amorphous fructose is present in an amount of at least 0.1wt % relative to the total mass of the fructose; and/or wherein thewater is present within the matrix phase in an amount of at least 0.2 wt% relative to the total mass of the fructose; and/or wherein thedispersed phase is present in an amount of at least 20 wt % relative tothe total mass of the fructose.
 9. The fructose of claim 1, wherein thefructose is in the form of a powder comprising particles having a D50 ofat least 10 μm.
 10. The fructose of claim 9, wherein the dry powdercoating contains coating particles, said coating particles having a D50that is at least 15% smaller than the D50 of the particles forming thepowder.
 11. The fructose of claim 1 having one or more of: a solubilityof at least 700 g/l; a CIELAB L* value of at least 85; a flowabilitybetween 20 and 45 degrees; a hydrophilicity between 15% and 50%.
 12. Apowder containing the fructose of claim
 1. 13. A method of manufacturingsolidified fructose comprising: (i) Providing an aqueous fructosesolution having a dry substance (DS) of at least 80 wt % relative to thetotal mass of the solution; (ii) Providing a powder containing particlescomprising a carbohydrate material; (iii) Adding the powder to theaqueous fructose solution to obtain an aqueous slurry having a glasstransition temperature (T_(g)); (iv) Quick cooling the aqueous slurry toa temperature of at most the T_(g) of said slurry thereby obtaining aproduct containing solidified fructose; (v) Optionally milling theproduct containing the solidified fructose and/or coating the solidifiedfructose or the milled solidified fructose.
 14. The method according toclaim 13 wherein the solidified fructose is a fructose in solid formaccording to claim
 1. 15. (canceled)
 16. The fructose according to claim2, wherein the carbohydrate crystals comprise fructose and one or moreother carbohydrate(s), wherein the one or more other carbohydrate(s) arepreferably selected from sweeteners and polyols.
 17. A fructoseaccording to claim 2, wherein the carbohydrate crystals consist offructose and wherein the fructose in solid form is coated with a drypowder coating that is different from fructose or does not consist offructose.
 18. The method according to claim 13 wherein the solidifiedfructose is a fructose in solid form according to claim 12.